eZ\Publish\Core\Persistence\Legacy\Content\UrlAlias\SlugConverter::convert PHP Method

    public function convert($text, $defaultText = '_1', $transformation = null)
    {
        if (!isset($transformation)) {
            $transformation = $this->configuration['transformation'];
        }
        if (strlen($text) === 0) {
            $text = $defaultText;
        }
        if (isset($this->configuration['transformationGroups'][$transformation]['commands']) && !empty($this->configuration['transformationGroups'][$transformation]['commands'])) {
            $text = $this->transformationProcessor->transform($text, $this->configuration['transformationGroups'][$transformation]['commands']);
        }
        return $this->cleanupText($text, $this->configuration['transformationGroups'][$transformation]['cleanupMethod']);
    }

 /**
  * Internal method for creating global or custom URL alias (these are handled in the same way).
  *
  * @throws \eZ\Publish\Core\Base\Exceptions\ForbiddenException if the path already exists for the given language
  *
  * @param string $action
  * @param string $path
  * @param bool $forward
  * @param string|null $languageCode
  * @param bool $alwaysAvailable
  *
  * @return \eZ\Publish\SPI\Persistence\Content\UrlAlias
  */
 protected function createUrlAlias($action, $path, $forward, $languageCode, $alwaysAvailable)
 {
     $pathElements = explode('/', $path);
     $topElement = array_pop($pathElements);
     $languageId = $this->languageHandler->loadByLanguageCode($languageCode)->id;
     $parentId = 0;
     // Handle all path elements except topmost one
     $isPathNew = false;
     foreach ($pathElements as $level => $pathElement) {
         $pathElement = $this->slugConverter->convert($pathElement, 'noname' . ($level + 1));
         $pathElementMD5 = $this->getHash($pathElement);
         if (!$isPathNew) {
             $row = $this->gateway->loadRow($parentId, $pathElementMD5);
             if (empty($row)) {
                 $isPathNew = true;
             } else {
                 $parentId = $row['link'];
             }
         }
         if ($isPathNew) {
             $parentId = $this->insertNopEntry($parentId, $pathElement, $pathElementMD5);
         }
     }
     // Handle topmost path element
     $topElement = $this->slugConverter->convert($topElement, 'noname' . (count($pathElements) + 1));
     // If last (next to topmost) entry parent is special root entry we handle topmost entry as first level entry
     // That is why we need to reset $parentId to 0
     if ($parentId != 0 && $this->gateway->isRootEntry($parentId)) {
         $parentId = 0;
     }
     $topElementMD5 = $this->getHash($topElement);
     // Set common values for two cases below
     $data = array('action' => $action, 'is_alias' => 1, 'alias_redirects' => $forward ? 1 : 0, 'parent' => $parentId, 'text' => $topElement, 'text_md5' => $topElementMD5, 'is_original' => 1);
     // Try to load topmost element
     if (!$isPathNew) {
         $row = $this->gateway->loadRow($parentId, $topElementMD5);
     }
     // If nothing was returned perform insert
     if ($isPathNew || empty($row)) {
         $data['lang_mask'] = $languageId | (int) $alwaysAvailable;
         $id = $this->gateway->insertRow($data);
     } elseif ($row['action'] == 'nop:' || $row['is_original'] == 0) {
         // Row exists, check if it is reusable. There are 2 cases when this is possible:
         // 1. NOP entry
         // 2. history entry
         $data['lang_mask'] = $languageId | (int) $alwaysAvailable;
         // If history is reused move link to id
         $data['link'] = $id = $row['id'];
         $this->gateway->updateRow($parentId, $topElementMD5, $data);
     } else {
         throw new ForbiddenException("Path '%path%' already exists for the given language", ['%path%' => $path]);
     }
     $data['raw_path_data'] = $this->gateway->loadPathData($id);
     return $this->mapper->extractUrlAliasFromData($data);
 }